Friction spinning apparatus

Abstract

 A friction spinning apparatus includes a yarn winder (P, 30, 36) and a pair of friction spinning rollers (1, 2) of which one roller (2) is perforated and provided with a suction slot which is opened and closed on rotation of a piecing lever (28), means being provided for interconnecting operation of the piecing lever (28) with, on the one hand, restoration of the winding operation and, on the other hand, restoration of fibre feed to the nip between the two friction spinning rollers.
Preferably the interconnecting means comprise a pair of cams (31 and 32) on the drive shaft (27) linked to the piecing lever (28) and co-operable with respective switches (34 and 35) to control drive to the fibre feed roller (37) of the fibre-opening unit and also the package lift mechanism to initiate winding.

Description

[0001] In our Published European Patent Application 0 052 412 there is disclosed a method of piecing in which the rotation of an inner sleeve or baffle within a perforated friction spinning roller effects opening of the suction slot so that suction is applied at the nip between the two friction spinning rollers along the yarn formation region.

[0002] Rotation of that baffle needs to be carefully timed in relation to (a) the initiation of fibre feed to the beater and (b) the start of the winding operation so that the fibre feed arrives at the yarn formation region correctly timed relative to the start of winding, in order to allow the first few fibres to attach to the retracting seed yarn which is drawing the newly spun fibres with it through the doffing tube, the yarn withdrawal itself having been activated by the resumed package rotation. Furthermore, since the apparatus disclosed in our said Published European Patent Application 0 052 412 also employs a pre-piecing phase in which suction is progressively cut off along the slot in order to draw the seed yarn along the spinning chamber, the restoration of primary spinning suction to the suction slot too soon would negate the advantage of the progressive suction slot blanking off in the pre-piecing phase (to induce movement of the seed end through the doffing tube and along the yarn formation region), and since the application of suction too late will result in fibres landing in regions remote from the nip between the two friction spinning rollers and thereby clogging the entire open-end spinning chamber, the timing of the restoration of suction in relation to the initiation of the winding operation is also critical.

[0003] Whereas previously that timing has been decided as a result of the skill of the operator of the friction spinner, we now propose to provide a semiautomatic piecing system independent of operator skill.

[0004] Accordingly, the present invention provides a friction spinning machine having at least one friction spinning station at which co-operating friction spinning rollers are positioned, at least one of the rollers being perforated; means for applying suction internally of said at least one perforated friction spinning roller; a winding station arranged to receive yarn spun in the nip between the friction spinning rollers at said friction spinning station; means for opening and closing a suction slot within said at least one perforated friction spinning roller; a fibre opening unit for opening fibres and delivering them to the nip between said friction spinning rollers; and means for operably interconnecting the suction slot opening and closing unit, the winding station and the fibre opening unit for ensuring that manual operation of a control to initiate operation of any one of these three components effects additionally initiation of operation of the other two of these components in the desired sequence and with a required relative timing for satisfactory piecing.

[0005] Preferably the opening and closing of the suction slot is controlled manually and the interconnecting means effects initiation of operation of both the winding station and the fibre feed in response to the degree of opening of the suction slot.

[0006] More preferably, the winding operation is initiated by lowering the package onto a rotating drive roll and the interconnecting means links the manual control for opening the suction slot and the package lowering mechanism.

[0007] Advantageously the fibre opening unit comprises a toothed beater roll and the interconnecting means links operation of a drive to the feed roller which supplies sliver to the toothed beater roll for opening, and effects initiation of said drive in response to the degree of opening of the suction slot. i

[0008] In order that the present invention may more readily be understood the following description is given, merely by way of example, with reference to the accompanying drawings in which:-

FIGURE 1 is an end elevational view, partly in section, of a friction spinning station incorporating the present invention;

FIGURE 2 is a view similar to Figure 1, but showing the exterior of the machine and additionally illustrating the winding station;

FIGURE 3 is a side elevational view showing the detail of the interior of the perforated roller shown in Figures 1 and 2; and

FIGURE 4 is a detail of Figure 3 showing the masking slot for ensuring progressive opening of the suction slot of the inner sleeve of the perforated roller.

[0009] The apparatus illustrated in Figures 1 to 4 is only slightly modified from that illustrated in our Published European Patent Application 0 052 412, the disclosure of which is incorporated herein by reference. Only sufficient detail of the apparatus of the earlier application will be described herein for exemplifying the improvements of this invention.

[0010] In particular, the apparatus illustrated in Published European Patent Application 0 052 412 shows a perforated roller 2 and a solid roller 1 operating alongside one another, with a baffle 6 defining a suction slot 7 very closely within the perforated roller 2, and a baffle 24 defining a masking slot 25 positioned closely within the cylindrical baffle 6. Rotation of innermost cylindrical baffle 24 defining the masking slot 25 is effected by means of a piecing lever 28 on a drive shaft 27 connected to the baffle 24.

[0011] Figure 2 of the present application shows the yarn Y leaving a doffing tube 29 and passing upwardly towards a winding station at which a package P of yarn rests on a winding roller 30 and is frictionally driven thereby for rotation such that the yarn passing over the package drive roller 30 and into the nip between the package P and the roller 30 becomes wound on the package P. Traversing of the yarn is effected by a conventional traversing mechanism (not shown).

[0012] When piecing is required, various functions are initiated, as shown in the following description which starts from a configuration after the friction spinning chamber has been cleared of any debris from previous spinning operations. This clearing operation is clearly illustrated and claimed in our Published European Patent Application 0 052 412. That cleaning operation is achieved by separating the solid roller 1 and the perforated roller 2 and rotating the piecing lever 28 in the anti-clockwise direction.

[0013] In order to prepare the apparatus for piecing up, the two friction spinning rollers 1 and 2 will be in their nip-defining configuration and the lever 28 is moved in the clockwise direction against spring-biasing, thereby progressively shutting off the suction slot 7 starting from the end nearer the piecing lever 28 and ending in a position where the end of the suction slot 7 remote from the lever 28 is exposed to suction. During this pre-piecing clockwise rotation of the lever 28, the end of the seed yarn for piecing, withdrawn from the package P,is introduced into the doffing tube 29 and the progressive suction shut-off will draw the yarn along the length of the yarn formation line. To allow this introduction of yarn to the doffing tube 29, the package P remains clear of the drive roller 30 (and indeed it will have been clear of that roller during the earlier part of the piecing and cleaning operation in order to allow the loose end of the yarn to be found from the package).

[0014] As the piecing lever 28 is released from this clockwise-rotated position the suction slot 7 is opened along its full extent (although in a very rapid operation which spreads the influence of the suciton from the end furthest away from the lever 28 until eventually the entire slot length is opened), and during this motion of the lever 28 and of the inner baffle 24 two cams 31 and 32 fast on the drive shaft 27 rotate in the anti-clockwise direction and cause respective switches 34 and 35 to trip in order, on the one hand, to energise a clutch to drive the conventional fibre feed roller 37 to beater roll 38 of the fibre opening unit and, on the other hand, to de-energise the package-lifting solenoid 36 (Figure 2) which until that moment holds the package P clear of the friction drive roller 30.

[0015] The angular positioning of the two cams 31 and 32 can be varied in order to adjust for variables such as the yarn count being spun, or differences in the friction on the package lifting mechanism which might result in a slightly later contact of the package P with the drive roll 30. It is thus possible to adjust the timing of either or both of the cams 31 and 32 in relation to the rotation of the drive shaft 27, and for this purpose the cams may be marked with indicia to facilitate adjustment.

[0016] From the above, it will be appreciated that the friction spinning station illustrated is capable of a piecing-up operation which is virtually independent of the skill of the operative and yet which is much simpler and cheaper than the fully automatic type of spinning machine in which a doffer robot will first of all arrive at the spinning station and exchange the full package for an empty package support tube, and later a piecer-cleaner robot will attend on that spinning station (or will separately arrive at the spinning station if there has been an end break before completion of the package build-up), and the operations of cleaning the friction spinning chamber and of piecing up are carried out fully automatically. The relatively cheap and simple apparatus provided for by the present invention can be adjusted to accommodate various variable parameters of the spinning operation and allows the operative to effect piecing-up without the need to lift and lower the package manually, and without the need to start the fibre feed manually.

[0017] Although the above description refers to manual operation of the blanking baffle 24 and automatic initiation of the package winding operation (by lowering of the package) and of the fibre feed, it will of course be understood that either the package lowering or the fibre feed initiation can be the manually effected variable, in which case a suitable timing system may be needed for linking the three functions in such a way that the operator is capable of carrying out those three operations singlehandedly while introducing the seeding end of the yarn into the doffing tube 29.

[0018] Throughout the above description we have referred to one of the two rollers as being perforated, but it will of course be understood that the same principles of the present invention may be applied where both rollers are perforated. Likewise, although parallel cylindrical rollers have been illustrated, there are various other possibilities, for example hyperboloidal rollers, as is well known in the art.

[0019] Furthermore, although the description of the present invention refers throughout to the type of suction slot closing and opening action illustrated in these drawings and also in our Published European Patent Application 0 052 412, the piecing system offered may readily be incorporated in a friction spinning apparatus in which an alternative form of suction cut-off and restoration mechanism is employed.

Claims

1. A friction spinning machine having at least one friction spinning station comprising co-operating friction spinning rollers (1 and 2) at least one (2) of which is perforated; means (24) for applying suction internally of said at least one perforated friction spinning roller; a winding station (P, 30) arranged to receive yarn spun in the nip between the friction spinning rollers at said friction spinning station; means (25, 27) for opening and closing a suction slot (7) within said at least one perforated friction spinning roller; a fibre-opening unit (37, 38) for opening fibres and delivering them to the nip between said friction spinning rollers; characterised by means (34, 35, 36) for operably interconnecting the suction slot opening and closing means (25, 27), the winding station (P, 30), and the fibre-opening unit (37, 38) for ensuring that manual operation of a control (28) to initiate operation of any one of these three components effects additionally initiation of operation of the other two of these components in the desired sequence and with a required relative timing for satisfactory piecing.

2. Friction spinning apparatus according to claim 1, characterised in that the manually-operable control (28) effects opening and closing of the suction slot (7) within the perforated roller, and in that the interconnecting means links operation of the means (25, 27) for opening and closing the suction slot and operation of the means (37) for feeding fibres to the fibre-opening unit (38), with operation of said manually operable control (28).

3. Friction spinning apparatus according to claim 2, characterised in that the means (25, 27) for opening and closing the suction slot comprise a parallelogram-shaped slot (25) defined by a rotatable baffle (24) within a fixed baffle (6) of the perforated friction spinning roller.

4. Friction spinning apparatus according to any one of claims 1 to 3, characterised in that only one (2) of the rollers is perforated and the other (1) is imperforate.

5. Friction spinning apparatus according to any one of claims 1 to 4, characterised in that the winding station comprises a drive roll (30) for frictionally engaging a package (P), and means (36) for lifting and lowering the package, whereby winding ceases when the package is lifted clear of the drive roll, and is re-started when the package is lowered onto the drive roll.

6. Friction spinning apparatus according to claim 5, characterised in that the interconnecting means comprises a pair of cams (31, 32) mounted on a drive shaft (27) to the means for opening and closing the suction slot (7) within said at least one perforated roller, and switches (34, 35) co-operable with said Cams for initiating lowering of the package (P) on the one hand, and initiation of rotation of the fibre feed roller (37) of a fibre opening unit on the other hand, in the desired timing in relation to opening of the suction slot.

7. Friction spinning apparatus according to claim 6, further characterised by including means for adjusting the positioning of said cams (31, 32) independently of one another, in relation to the drive shaft (27).

8. Friction spinning apparatus according to claim 6 or 7, characterised in that said manually operable control comprises a lever (28) fast on said drive shaft (27).

Drawing